Floor crane with adjustable legs



P" 1955 R. R. STRATTON FLOOR CRANE WITH ADJUSTABLE LEGS 2 Shets-Sheet 1Filed June 19, 1951 7 5 5 w d w. a a a T l l w m T. 5 T ,v I 7 7 u 1 3 1f V an. m m a ll. 0 a 7 n, a F1 8 o- Z M x m a I 5 AM a Z 2 6 v 5 2 22MB .2 5 n j a fiztk. 3m 9 4 a /V 1 l 52 6 8 f 9 5 a W H 9 4 1 l 4 a A7' TOQ/VEYS.

A ril 12, 1955 R.- R. STRATTON 2,706,120

FLOOR CRANE WITH ADJUSTABLE LEGS Filed June 19 1951 2 Sheets-Sheet 2 J9J5 64 61 J/ 'lllnllllufllllliln I INVENTOR.

Po/vAm A? 5 7 7 70 BY United States Patent Office 2,706,120 PatentedApr. 12, 1955 FLOOR CRANE WITH ADJUSTABLE LEGS Ronald R. Stratton,Cleveland, Ohio, assignor to Stratton Equipment Company, Cleveland,Ohio, a corporation of Ohio Application June 19, 1951, Serial No.232,337

3 Claims. (Cl. 280-35) This invention relates to a floor crane and, moreparticularly, to a floor crane characterized by a high degree ofadaptability to a variety of different uses.

In automotive repair shop practice, as, for example, in shops forrepairing automobiles, trucks, tractors, etc., it is usually considereddesirable to have a floor crane available for lifting engines and otherheavy parts; at the same time, it is usually desirable to have the cranereadily maneuverable and of such dimensions that it can pass throughdoorways of ordinary widths. The usual crane that is designed to passthrough doors of ordinary widths cannot be used in certain situationsbecause the legs are too close together to permit the crane to be placedin position to lift the load; while heavy-duty cranes of largerdimensions are generally too wide to pass through the usual shopdoorways. A floor crane that is both maneuverable and adaptable tovarious purposes is desirable in automotive repair shops and othershops.

Accordingly, it is an object of the present invention to provide a floorcrane that is readily maneuverable through shop and like doors ofordinary widths, and that also can be used where wide-spread legs arerequired in order to put the crane in position for lifting. To that end,the invention provides a floor crane characterized by legs which innormal position parallel the boom but nevertheless are susceptible ofbeing adjusted to a variety of positions in each of which they canstraddle obstructions wider than the normal space between the legs. Itis of course quite necessary that the floor crane be so constructed thatwhen the legs are spread to straddle a wide object of this sort, theinherent stability of the crane will successfully resist any tendency toupset.

A further object of the invention contemplates the provision of meansfor adjusting the legs to any one of a relatively wide variety ofpositions in certain of which the crane as a whole will be of narrowwidth, thereby permitting it to pass through doorways of ordinarydimensions, and in others of which the fioor crane will have thecapacity for straddling wide objects. To this end, the inventionprovides simple, foolproof adjusting means by which, when the desiredadjustment has been effected, the same can be retained as long asdesired,

after which the adjustment may by a very simple manual operation bemodified to provide a greater straddle, a lesser straddle, or nostraddle at all except such as characterizes the retracted position ofthe legs. It is of course desirable that the adjustment be susceptibleof being made quickly without undue trouble and the invention providesadjusting means designed with this and like considerations in mind.

It is a further object of the invention to provide a floor crane oflight but sturdy construction in which there is extensive surfacecontact between the platform mounting the superstructure and those partsof the legs which cooperate with the platform. To that end, theinvention contemplates the use of legs of a shape such that the upperand lower surfaces thereof bear with limited clearance against theelements making up the top and bottom of the mast-mounting platform.This construction has the advantage that there can be dissemination overa wide area of forces transmitted from one part to another, therebypermitting the use of an extremely simple pivotal connection at thepoints where the legs are coupled to the platform.

A further object of the invention is to provide a substructure for thefloor crane which is of built-up construction but which willnevertheless have adequate rigidity to resist bending forces, togetherwith a degree of strength of the order of that usually found only insub-structures of much heavier construction. To that end, the platformmounting the superstructure preferably consists of a simple base plateserving as the top of the platform, a suitable bottom structure, and,between them, web-like reinforcing means including a web-like shieldsurrounding the greater part, but less than all, of the periphery of theplatform. The leg structure, including the means for housing the castersat the rear of the legs, likewise is of built-up construction. The innerends of the legs are also of built-up construction and, as previouslymentioned, especially designed to provide extensive surface contact withoverlying and underlying parts of the platform.

Other objects and advantages of the invention will be apparent from thedescription which follows and from the accompanying drawings, in whichFigure 1 is a top plan of a floor crane incorporating the teachings ofthe invention; Figure 2 is a corresponding side elevation; Figure 3 is acorresponding bottom plan; Figure 4 is a sectional elevation on asomewhat larger scale as seen from line 4-4 of Figure 2; and Figure 5 isa section with parts in elevation, on the same scale as in Figure 4, asseen from line 5-5 of Figure 1.

In the drawings, Figures 1, 2 and 3 show, among other things, amast-supporting platform generally designated 1. Mounted on platform 1is a mast 2 characterized by a hollow portion 2a that serves as areservoir for oil or some other suitable hydraulic fluid and, abovehollow portion 2a, by a block 2b on which is mounted a boom 3. At theunsupported end of boom 3 are the usual chain 4 and hook 5. At a pointintermediate its two ends, boom 3 is connected to a piston rod 6 on thelower end of which is carried a piston (not shown) that coacts with ahydraulic cylinder 7 supported by means of a yoke 8 on an uprightmounting plate 9. Apart from platform 1, all of the elements of thesuperstructure so far mentioned, and also certain of the elementshereinafter mentioned, are of conventional construction.

As appears from Figures 1 and 2 of the drawings, platform 1 incorporatesa substantially flat base plate 11 to the upper face of which is welded,in addition to mast 2 and mounting plate 9, a hand-operated pumpassembly generally designated 12, such pump assembly including anoperating handle 13. Between hollow portion 2a of mast 2 and pumpassembly 12 is a first hose connection 14, such connection being shownin Figure l. Extending from pump assembly 12 toward cylinder 7 is asecond hose connection 15 terminating in a regulator 16 which isconnected to the lower end of cylinder 7 and from which a third hoseconnection 17 leads to a valve 18 rigidly mounted on and incommunication with hollow portion 2a of mast 2. Back of valve 18 as seenin Figure 2 is a fourth hose connection 19 connecting hollow portion 2aof mast 2 and the upper end of cylinder 7 at a point above the pistoncarried by piston rod 6.

Welded to base plate 11 and extending forwardly from mast 2 is anupright mounting plate 21 to which is pivotally connected a T-handle 22which is bifurcated at its lower end to permit it to straddle mountingplate 21. Mast 2 is strengthened by a vertical stiffening flange 23welded to it in the relation shown in Figure 2. Welded to and extendingforwardly from stiffening flange 23 is an inclined brace 24 of bar stockwhich passes through the bifurcated portion of T-handle 22, such bracebeing welded at its lower end to base plate 11. Extending laterally inopposite directions from mast 2 are two inclined tubular braces 25 and26, such tubular braces being welded at their upper ends to hollowportion 2a of mast 2 and at their lower ends to base plate 11.

Base plate 11 has a forwardly extending portion of semi-circular formwhich forwardly extending portion is designated 27 in Figure 1. It alsohas a rearwardly extending portion designated 28, such rearwardlyextending portion taking the form of a shallow rectangle. The twoportions 27 and 28 are not separate but integral with each other, beingpart of the same piece of stock. Depending from base plate 11 as shownin Figure 2 and extending rearwardly in both directions from the frontend of platform 1 is a web-like shield 29 of the nature of an apron.Shield 29 is welded to the lower face of base plate 11. It isco-extensive with it except near the squared-01f trailing edge 28a atthe rear of the base plate, where it stops short of such trailing edge.Shield 29, which thus encompasses the greater part of the periphery ofplatform 1, provides a measure of protection for the two casterassemblies 31 shown in Figure 3.

Caster assemblies 31, each of which is mounted on the lower face of baseplate 11 and includes a caster wheel 32 mounted for free swivelingmovement through an arc of 360, support and impart mobility to platformI.

As appears from Figure 3, the lower face of base plate 11 is furtherprovided with a triangular reinforcing web 33 and a forwardly extendingreinforcing web 34, both of which are welded to base plate 11.Triangular reinforcing web 33 is made up of three like portions 33a, 33band 330. The latter 33c, is at the rear and blocks off a large part ofthe area behind shield 29, which area would otherwise be open from theback. Together,

triangular reinforcing web 33 and forwardly extending reinforcing web 34divide the lower face of base plate 11 into compartments, of which thereare two like compartments, one a mirror image of the other, inside-byside relation. It is in these compartments that the casterassemblies are mounted. A horizontally extending reinforcing plate 35,shown as rectangular in Figure 3. is used to interconnect parts 33a, 33band 33c of triangular reinforcing web 33, thus forming a part of andfurther stiffening the reinforcing system underlying base plate 11.Along with other elements about to be described, reinforcing plate 35goes to make up the bottom structure of platform 1.

As shown in Figure 3, triangular reinforcing web 33 is flanked bypolygonal reinforcing plates 36 and 37. The latter are in the same planeas rectangular reinforcing plate 35 and, like it, go to make up part ofthe bottom structure of the platform. They extend outwardly to web-likeshield 29 from triangular reinforcing web 33 and rectangular reinforcingplate 35, being welded thereto along their outer and inner edges. Asappears from Figure 2 of the drawings, flanking plates 36 and 37 extendrearwardly somewhat beyond the limits of the rearwardly extending partsof web-like shield 29, terminating directly below the squared-offtrailing edge 28a of base plate 11. This construction providesimmediately above flanking plates 36 and 37 two open-ended pocket-likechambers 38 and 39, best shown in Figure 4. Such chambers, which areconsiderably wider at the forward ends than at the rear ends thereof,terminate at the rear of the platform in the plane of part 330 oftriangular reinforcing web 33.

In substantially this same plane are located pivot pins 41 and 42, whichtake the form of incompletely threaded bolts or similar elements havingheads 41a and 42;: that can bear upon base plate 11 just forward oftrailing edge 28a. Pivot pins 41 and 42 pass through pairs of alignedopenings (not shown) in base plate 11 and flanking plates 36 and 37.They are long enough so that their threaded portions, which are at thelower ends thereof, project through flanking plates 36 and 37 as shownin Figure 4, thus permitting nuts 43 and 44, which are preferably of theself-locking type, to be applied thereto. Pivot pins 41 and 42 areprovided in order to mount and impart a capacity for swinging movementto stabilizing legs 45 and 46, the inner ends of which project intochambers 38 and 39, respectively. These simple pivot pins are adequatefor the purpose in view of the fact that, as will appear, theconstruction of the platform and legs imposes on them only relativelylight loads. If the construction of the platform and legs werediiferent, pivot pins of the nature of king pins might be necessary.

Each of legs 45 and 46 consists as shown in Figures 4 and of arelatively wide downwardly facing upper channel member 47 interiorlystiffened by means of a plate 48 that is welded to the horizontalportion thereof and a relatively narrow upwardly facing lower channelmember 49 that is similarly stiffened by means of a plate 50. Lowerchannel member 49 tits closely within and is welded to upper channelmember 47 to provide a highly rigid construction. Aligned holes (notshown) for pivot pins 41 and 42 are drilled through upper channel member47 and stiffening plate 48 and lower channel member 49 and stiffeningmember 50, such holes being arranged to register with aligned holes (notshown) in base plate 11 and flanking plates 36 and 3"] where pivot pins41 and 42 pass through platform 1.

By locating the holes in base plate 11 and flanking plates 36 and 37substantially in the plane of part 330 of triangular reinforcing web 33,they are removed slightly from the rear extremities of platform 1 butnevertheless in a position to permit relatively wide swinging movementof the opposite ends of legs 45 and 46 between limits indicated by thesolid-line positions, in which they parallel boom 3, and theoutwardly-angled positions represented by dotted lines 45' and 46' inFigure 3. Legs 45 and 46 can be swung outwardly to an extent greaterthan that indicated by the dotted-line positions, such relatively wideoutward swing being made possible by the fact that chambers 38 and 39are wider at their forward ends rather than at the rear thereof and thefact that web-like shield 29 terminates as previously explained somedistance short of the ends of base plate 11 and flanking plates 36 and37. The straddling of wide obstacles thus becomes possible.

By locating pivot pins 41 and 42 as shown in the drawings, it alsobecomes possible to permit the inner ends of legs 45 and 46 to projectinwardly for a considerable distance within pocket-like chambers 38 and39. The fit of legs 45 and 46 therein is a close fit with only a slightoverall clearance with the result that there is extensive area contactbetween each of legs 45 and 46 on one hand and, on the other, theportions of base plate 11 and fianking plates 36 and 37 defining the topand bottom walls of chambers 38 and 39. By virtue of this extensive areacontact between the inner ends of legs 45 and 46 and the elements whichoverlie and underlie them, there is wide dissemination of the forcesacting on these parts with resulting decrease in the unit pressure. Thisis what makes possible the simple construction characterizing pivot pins41 and 42.

Near the inner ends thereof, legs 45 and 46 are provided with alignedopenings (not shown) for receiving a locating pin 51, best shown inFigure 5, and a like locating pins 53 on the opposite side ofplatform 1. Locating pin 51 consists of a head portion 51a and a shankportion 51b; similarly, locating pin 53 consists of a head portion 53aand a shank portion 53b. Cooperating with locating pins 51 and 53,respectively, are two series of holes 52 and 54 in base plate 11,wherein the holes of each series are disposed in arcuate arrangement asindicated in Figure 1. Pivot pins 41 and 42 are disposed at the centers,i. e., at the ends of the radii, of the arcs defined by the two seriesof holes 52 and 54, respectively. Like series of holes, shown in Figure3, are formed in alignment therewith in flanking plates 36 and 37.

If it is desired to retain legs 45 and 46 in the retracted positionsshown in full lines in Figures 1 and 3, locating pins 51 and 53 arepassed through the outermost holes of each series and the aligned holesin the two legs. if it is desired to spread legs 45 and 46 to straddlerelatively wide obstacles, such as the wheels at the front or rear of anautomobile, locating pins 51 and 53 may be removed from the holes inwhich they appear in Figure 1, after which the legs may be angledoutwardly as desired and locating pins 1 and 53 reinserted in otherholes positioned inwardly thereof in same series. Generally, during suchtime as the floor crane is in actual use, legs 45 and 46 will be angledto one of the positions represented by dotted line positions 45 and 46'in Figure 3. When it becomes desirable to move the crane from oneposition to another, legs 45 and 46 may but need not necessarily beretracted to the position shown in full lines in Figures 1 and 3;however, in moving the crane through relatively narrow openings, such assmall doorways, it will usually be found necessary to retract legs 45and 46.

The pin-and-hole means for locating legs 45 and 46 with respect toplatform 1 and the longitudinal axis of the crane as a whole thusprovide a desirably wide range of positions between extremes representedby retracted and fully spread positions.

The forward ends of legs 45 and 46 may be closed off, if desired,although there is no particular advantage to closing them. They aretherefore shown in the drawings as open. However, the opposite or farends of legs 45 and 46 will ordinarily be closed off by cross plates 55which are preferably welded thereto as indicated in Figure 5.Ordinarily, cross plates 55 will be considerably larger in area than thetransverse cross sections of legs 45 and 46, being both longer andwider. To them is welded a web-like shield 56 that is U-shaped as seenfrom above. To its top edges is welded a U-shaped cover plate 57. A topgusset 58 and side gussets 59, so shaped as to conform to the needs ofthe situation, are welded in place as shown to provide rigidity for therear caster housings provided at ends of legs 45 and 46 by cross plates55, shields 56 and cover plates 57.

The rear caster assembly in each case consists of a mounting plate 61,which is bolted or otherwise fastened to the lower face of cover plate57, a free-swiveling caster bracket 62, and a heavy-duty caster wheel63. The parts forming caster bracket 62 have rigidly associated withthem a forwardly projecting extension 64, such extension beingtongue-shaped and rather closely underlying cover plate 57. Extension 64is provided with an opening (not shown) for receiving a locating pin 65provided with a head portion 65a and a shank portion 65b. In general,locating pin 65 serves the purpose of keeping caster wheel 63 fromswiveling when the fioor crane is being moved from one position toanother with the legs in retracted position.

When the floor crane as a whole is in such position, as in moving itthrough a doorway, pin 65 passes through a centrally located opening(not shown) in cover plate 57 and thence into the underlying opening inextension 64, thus holding caster bracket 62 and caster wheel 63 in aposition in which they are aligned with the longitudinal axis of the legwith which they are associated. If it is desired to permit the casterassembly to have swiveling movement within the limits permitted by theside walls of U-shaped shield 56, locating pin 65 is withdrawn andreinserted in an extra opening 66. When locating pin 65 is in thisposition, it does not interfere with extension 64, which is free to movefrom one side to the other in an arcuate path. Thus caster bracket 62and caster wheel 63 have a corresponding degree of freedom for swivelingmovement within the limits imposed as above explained by the sidewallsof U-shaped shield 56.

Although it is apparent that numerous changes in construction arepossible, the above-described arrangement of parts is especiallyadvantageous in that it provides a highly rigid, stable floor cranecharacterized by an unusually high degree of adjustability andadaptability. In traveling position, i. e., the position in which thelegs parallel the boom, the floor crane has adequate lateral stabilityfor all ordinary uses; but by moving the legs outwardly into one of theseveral alternative positions which the pin-and-hole adjusting meansmake possible, even greater stability is provided. At the same time, thespread position of the legs permits the crane to straddle and to be usedin close proximity to relatively wide objects. By virtue of the built-upnature of the substructure and particularly the extensive area contactbetween the legs and the platform, the forces imposed on boom, mast andcylinder by the load being lifted are transmitted to and distributedover broad surfaces at the inner ends of the legs, whereby the unitpressures thereon are minimized. A flexible connection between the legsand platform is provided without thereby introducing excessivedeflection into any of these parts, this notwithstanding use of thefloor crane to lift very heavy objects.

It is intended that the patent shall cover, by summarization in theappended claims, all features of novelty resident in the invention.

What is claimed is:

1. In a floor crane, substructure comprising a substantially flat baseplate; a web-like shield depending from the base plate around a largepart, but less than all, of the periphery thereof; reinforcing meansdepending from the base plate interiorly of such peripheral shield;bottom structure paralleling the base plate, such bottom structureextending outwardly from the reinforcing means to the peripheral shield;pivot pins extending between the base plate and the bottom structuretoward the rear of the substructure; stabilizing legs pivoted on saidpivot pins, said-stabilizing legs extending generally rearwardly beyondthe limits of the substructure but projecting inwardly at their innerends beyond said pivot pins at least far enough to permit of substantialarcuate movement of such inner ends in the space between the reinforcingmeans and the peripheral shield.

2. In a floor crane, substructure comprising a substantially flat baseplate; a plurality of caster assemblies on the base plate; a web-likeshield depending from the base plate, such shield extending around thegreater part, but less than all, of the periphery thereof; web-likereinforcing means depending from the base plate interiorly of suchperipheral shield; bottom structure paralleling the base plate, suchbottom structure extending outwardly from the reinforcing means to theperipheral shield; a plurality of stabilizing legs projecting outwardlybeyond the peripheral shield, the inner ends of said stabilizing legsbeing pivotally mounted in the space between the reinforcing means andthe peripheral shield; a caster housing at the end of each leg, suchcaster housing comprising a cross plate, a web-like shield, and a coverplate; and a caster assembly in each of the caster housings.

3. In a floor crane, substructure comprising a flat base plate having arounded forward portion; two like caster assemblies mounted on the baseplate below the forward portion thereof; a web-like shield dependingfrom the base plate, such shield extending around said forward portionand thence rearwardly through the greater part, but less than all, ofthe periphery of the base plate; weblike reinforcing means of generallytriangular configuration depending from the base plate interiorly ofsuch peripheral shield, one of the apices thereof pointing forward; flatbottom structure paralleling the base plate, such bottom structureextending outwardly from the sides of said reinforcing means to theadjacent side portions of the peripheral shield; two pivot pinsextending between and supported by the base plate and the bottomstructure; two like stabilizing legs mounted on said pivot pins, saidstabilizing legs extending generally rearwardly beyond the limits of thesubstructure but projecting inwardly at their inner ends at least farenough to permit of substantial arcuate movement of such inner ends inthe space between the reinforcing means and the peripheral shield; acaster housing at the end of each of the two stabilizing legs, each ofsaid caster housing comprising a transversely extending cross plate, afiat cover plate, and a depending web-like shield; a caster assemblyrotatably mounted in each of the two caster housings; and means on eachof the cover plates for optionally permitting or preventing swiveling ofthe casters.

References Cited in the file of this patent UNITED STATES PATENTS115,779 Stafiord et a1. June 6, 1871 649,300 Hall et a1. May 8, 19001,193,551 Howard Aug. 8, 1916 1,429,216 Arwine Sept. 19, 1922 1,846,567Murray, Jr. Feb. 23, 1932 2,174,415 Curtis Sept. 26, 1939 2,517,813Wallace Aug. 8, 1950 2,553,955 Berchtold May 22, 1951 2,613,083 MoludyOct. 7, 1952

